The National Science Foundation has given a $300,000 grant to Xiaoqing Song, an assistant professor in the Electrical Engineering and Computer Science Department, to support his research project focused on advancing high density and high-operation-temperature traction inverters. Song's project explores the integration of gallium ooxide packaged power modules to enhance the power density and temperature range of electric vehicles.

Collaborating with the National Renewable Energy Laboratory, the project sets out to innovate power module packaging, establish reliable strategies for gallium oxide power devices and demonstrate the capabilities of a high density, high temperature traction inverter.

"By eliminating technical barriers for gallium oxide device integration, this project will foster the development of next-generation, high density and high-operation-temperature power converters," Song said.

The traction inverter, responsible for converting stored direct current (DC) power into alternating current (AC) power to drive electric motors, stands to benefit significantly from gallium oxide technology. Song said, "Gallium oxide can make the traction inverter smaller, lighter, more efficient and capable of operating across a wider range of temperatures.

"Gallium oxide has a larger band gap energy compared to conventional silicon and wide band gap semiconductors. It enables high breakdown electrical strength, low intrinsic carrier concentration and correspondingly high operation temperatures," Song said.

One challenge addressed in the project is the low thermal conductivity of gallium oxide, which hinders efficient heat removal. Song outlines the plan to develop advanced power module packaging techniques that enable low thermal resistance, low parasitic inductances and high-temperature operation capability.

"National Renewable Energy Laboratory (NREL) has significant experience in power module simulation, fabrication and characterization, as well as world-class experimental and lab capabilities for evaluating and designing efficient and reliable power electronics systems. The PI will collaborate with them to design and develop a gallium oxide-based high density and operation-temperature traction inverter for automotive applications. This project will help establish a long-term partnership with NREL that can catalyze further research and development of ultra-wide bandgap power semiconductor devices," Song said.

Song shared that the collaboration with the National Renewable Energy Laboratory aims to design and develop a gallium oxide-based high density and high-operation-temperature traction inverter for automotive applications, fostering a long-term partnership that can drive further research in ultra-wide bandgap power semiconductor devices.

"Other applications include power grids, data centers, renewable energy, space and defense, etc.," Song added.

The success of the project, he believes, will provide valuable insights into gallium oxide device modeling, packaging, gate driving, protection and application in power converters. These advancements are expected to catalyze progress in transport electrification and the deployment of gallium oxide technology in challenging environments.

"The research achievements and experiences gained in the fellowship will sustain and promote the PI's future multi-disciplinary research activities in semiconductor devices, multiphysics analysis, power module packaging and high performance power electronics. Other broader impacts also include the education and development of the next generation workforce in STEM (science, technology, engineering and math), the encouragement of more women and underrepresented minorities in electrical engineering, especially in the area of wide and ultra-wide bandgap semiconductor devices, power module packaging and power electronics with hands-on lab experiences," Song said.